The invention relates generally to a Mach-Zehnder Interferometer (MZI). In particular, the invention relates to an MZI using concatenated unseparated crystals.
A Mach-Zehnder Interferometer (MZI) has several optical paths between the input and the output beam-splitters. When one of the optical paths is provided as a reference path, the other optical path can contain an element whose optical path length (product of displacement and index of refraction) can be monitored. Either of the outputs of the MZI is sensitive to optical wavelength phase level fluctuations.
A conventional free-space MZI constitutes a relatively simple device that uses a monochromatic laser, two beam-splitters, two mirrors and screen(s) or camera(s) for detection of the interference profile, interferogram. The conventional MZI configuration typically employs an optical table with regularly tapped holes for holding opto-mechanical mounts that anchor the mirrors and beam-splitters, which are the core components of the MZI. The opto-mechanical mounts typically have micrometer, pivots, and springs in arrangements that are used to finely manipulate the beams of light to cause interference at the output of the MZI. However, the conventional free-space MZI after alignments is neither compact nor stable, due in part to the opto-mechanical mounts.